


Crossing Universes, Now Staring Suicidal Bastards and Tired Chibis

by Nilaic



Series: Crossing Universes Dimension [1]
Category: Katekyou Hitman Reborn!, 文豪ストレイドッグス | Bungou Stray Dogs
Genre: Alternate Universe - Canon Divergence, BAMF Dazai Osamu (Bungou Stray Dogs), BAMF Nakahara Chuuya (Bungou Stray Dogs), Dazai Osamu Being An Asshole (Bungou Stray Dogs), Dimension Travel, Dying Will Flames (Katekyou Hitman Reborn!), Gen, Mafia Soukoku | Double Black (Bungou Stray Dogs), Not Beta Read, Port Mafia Dazai Osamu (Bungou Stray Dogs), Post-Canon, Soukoku | Double Black (Bungou Stray Dogs), Unconventional Uses for Dying Will Flames
Language: English
Status: Completed
Published: 2020-12-01
Updated: 2020-12-02
Packaged: 2021-03-10 06:07:31
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 6
Words: 4,653
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27819493
Author URL: https://archiveofourown.org/users/Nilaic/pseuds/Nilaic
Summary: Tsuna needs help taking care of some Estraneo experiment subjects that had been attacking people left and right. But, all those he sent were killed or severely injured. What does he do? Summon the strongest people from another universe, obviously.Dazai and Chuuya just finished their last mission when they suddenly teleported to a strange place with strange people asking for their help. Dazai thinks it's quite amusing, and doesn't really mind helping as long as Chuuya isn't hurt, of course. Chuuya is so tired of Dazai's crap. But, he can't let his partner get killed, can he?So, this is the story of how Soukoku joined Vongola.
Series: Crossing Universes Dimension [1]
Series URL: https://archiveofourown.org/series/2037799
Comments: 5
Kudos: 75





	1. Introductions

**Author's Note:**

> Hey, just to clarify, Dazai has Snow flames, but cause of his ability, his flames also have to ability to neutralize. Neutralize what, and in what way? Well... you'll see. Chuuya doesn't have active flames. Cause his ability is enough. Dazai never met Oda in this world, so he never left the mafia. He is super protective of Chuuya, so think of it like Chuuya in this universe is Oda in original, in terms of how Dazai regards them. They care about each other very much. They're just tsunderes. 
> 
> Other than that, this is my first attempt at writing fanfiction! The first chapter is quite short, sorry. Please don't murder me, I'll try my best. Feel free to give me tips or corrections, if something is inaccurate. I'll try to fix it. Enjoy!(?)

**Notes for the Chapter:**

> By the way, the inspiration for Dazai's flame came from the work 'Balancing on a Knife', by RiKuEersa

Chapter One

Tsuna clutched the paper tightly in his hand. All twenty men sent to eliminate the threats were all found dead, their corpses scattered around the area. Recently, deaths had been occurring near the abandoned mansion which formerly belonged to the Estraneo Family. Apparently, the beings spotted lurking around the mansion looked like humanoid creatures with strangely elongated arms and legs, and had distorted facial features. They were suspected to be the result of experiments previously done by the Estraneo Family, though how they managed to hide for so long is unknown.

The twenty men sent were highly skilled, and should have been more than capable to complete the task and return. When Reborn, Takeshi and Lambo were sent, they returned heavily injured, and with their flames depleted.

Tsuna sighed and rubbed a hand over his face. His intuition was blaring warning signs left and right, clearly telling him NOT to send anyone else, or to go handle it himself. But he couldn't just ignore it. It might endanger him or his family in the future. So what should he do?

'We need someone able to take on the experiments...but who would be able to do that when even Reborn could not?' Tsuna thought.

His intuition was telling him something, but he couldn't make sense of it. Something about… Spanner, Giannini… The transporter!

Right, they had recently made a device able to bring over the strongest people from another universe. In theory, the people brought over could help them. But… they might not even be willing to help a bunch of random strangers, especially not at the risk of their own safety, seeing as a lot of men were killed trying to go after the experiments. *sigh* But he supposed he didn't have much choice, and if his intuition was suggesting it, well. It should be fine. Maybe.

\------

Tsuna stared at the machine. It was a flat circular device. Once they pressed the red button he currently held, the strongest person(s) would appear on said circular device.

"Tenth, are you sure this is a good idea?" Hayato asked from where he stood behind him, along with the rest of his guardians and the arcobaleno. They had been called here for safety, in case the people they brought over were hostile. Tsuna sighed, "Honestly, I'm not even sure myself, Hayato. But we don't have any other choice. I'm not going to let people die just because I was too cowardly to do this."

With that, Tsuna pressed the red button. Everyone watched with baited breath as smoke covered the machine. As it cleared, they spotted two figures. One was a bandaged(?) dark haired brunet and the other had red hair and wore a hat.

"Oi, shitty mackerel, what did you do this time?"

"Chuuya~ Do you have such little faith in me? I'm hurt~ I didn't do anything this time."

Tsuna blinked at the bickering duo, slightly confused. They were the strongest in their universe? Tsuna internally shook his head. No, no, appearances could be deceiving. He knew this. He shouldn't be so quick to judge.

"Excuse me?" Tsuna interrupted.

The hat wearing teen's(?) head snapped over at his voice, while the bandage covered man just casually glanced at him.

"I'm Tsunayoshi Sawada, and we brought you here to ask you for a favor, if you're willing to listen?"


	2. Perspective

**Summary for the Chapter:**

> Soukoku perspective

**Notes for the Chapter:**

> Time for Soukoku perspective. Meaning very much infuriated chibi and relatively amused bandage covered man.

Chapter 2

Chuuya grunted as he punched the last man, then turned to address the lazy ass currently seated on what remained of the wall after Chuuya threw two men at it.

"Ah, is Chuuya finally done?" Dazai asked with a teasing smile.

"What do you mean, finally done? All you did was sit around you suicidal ass!" Chuuya huffed. Honestly, the man was insufferable. Annoying, whiny, immature, and suicidal to boot, God knows how he managed to survive this long despite his constant attempts to end his life. Chuuya twitched at the thought of Dazai finally succeeding, his heart felt heavy and dread filled his body. No, he could not stand Dazai's constant whiny attitude, but he couldn't even begin to fathom living without his partner beside him.

Chuuya sighed as he went about destroying any remaining files the organization, called 'Bears', had on the Port Mafia. He supposed he just wouldn't let Dazai die, after all, if he didn't do it, no one would.

Dazai yawned from atop his perch. Blinking away the drowsiness that threatened to overtake him, he resolved to take a long nap. After all, he did use his flames quite a bit today.

With the mission completed, the duo left the premises, heading to the car parked nearby.

"Chuuya~ Are you sure you should drive? What if the police mistake you for a child? Then we'll get pulled over, and since you're so short, so one would believe you're an adult, you know?"

Chuuya twitched.

"Shut up mackerel, I'm too tired for your crap right now."

Dazai pouted. He sighed but complied, lying down on the comfortable seats for a quick nap.

\----No Longer Human----

"Oi wake up, I'm not carrying you into the building."

Dazai blinked awake, letting out a large yawn and getting out of the car. Just as he stopped beside Chuuya, to maybe give a jab or two, a large poof of… pink smoke(?) covered them.

Chuuya, annoyed, and way too tired for Dazai's pranks and jabs, turned to him and said, "Oi, shitty mackerel, what did you do this time?"

Dazai was mildly alarmed, but since nothing was obivously trying to kill them, well, it should be fine, for a bit at least. He took note of the group of people assembled in the room, but they were just staring at them, and the device(?) they were standing on. So they were the ones who brought them here… Wherever here was, because it sure as heck wasn't the garage of the apartment building he and Chuuya lived in.

"Chuuya~ Do you have such little faith in me? I'm hurt~ I didn't do anything this time." Dazai replied. He noted the guy at the front of the group, which he named Mr Spiky Hair, or Spiky for short, seemed slightly confused at their bickering. Ah, but Mr Spiky Hair recovered quickly, opening his mouth to interrupt Chuuya's response.

"Excuse me?" Mr Spiky Hair interrupted.

Chuuya snapped his head over to Spiky, also slipping his hand over to one of his guns he carried on him, but Dazai just casually glanced over. Well, let's see what they want.

"I'm Tsunayoshi Sawada, and we brought you here to ask you for a favor, if you're willing to listen?"

Hoh, a favor… Right after kidnapping them?

Dazai stepped toward Mr Spiky Hair, now Tsunayoshi, absently noting Chuuya cautiously following beside him.

"Hmm, a favor? And what could you possibly want from us?" Dazai asked. He glanced over the group, they had all tensed and grabbed their weapons when he stepped forward, so they were expecting a hostile reaction? Well, that makes sense. Who kidnaps random people to ask for favors? Obviously they might not be open to being kidnapped, so a negative reaction is expected.

Tsunayoshi seemed to gather his courage before answering his question.

"Ah… You see, we brought you here using that machine. It was made to bring the strongest persons from a different universe to our universe. We have a problem, there are some… hostile beings which are attacking people. However, we are unable to neutralize them, as everyone sent was either killed or injured to the point where they could no longer fight efficiently. So, we were left with only one option, which was to use the machine, and ask whoever shows up for a favor. In return, since we cannot send you back to your universe, we'll give you a place to stay, food to eat, and protection. If you don't want to help us, we won't begrudge you for it either. We'll let you leave."

Dazai considered the request. Hmm, need help eliminating threats, have weapons, wear suits, and have fighters at their disposal? Yup, that sounds like mafia alright. And apparently, they want Dazai and Chuuya to help them. Well, it's not a bad deal, really. And honestly, he's been quite bored recently, might as well help them out, considering they won't be able to return. This is also a good way to secure food and shelter.

Chuuya bristled beside him at the mention of not being able to return to their original universe. Uh oh, Chuuya's angry~

Chuuya POV  
The nerve! To just pull people here without even making sure they had a way to return them to their original universes. Not to mention asking them to risk their lives for a favor from a total stranger! He felt his lips pull down into a frown.

"We-" Chuuya started. "Eh, sure!" Dazai cut in.

...what.

Did Dazai just agree?

"Well, I mean I don't mind, but I dunno about Chuuya over there."

Chuuya glared at Dazai. If he disagreed, he would be forced to separate from Dazai, and considering he knew next to nothing about this universe, it wasn't a good idea. At least if they both rejected the offer, with Dazai's genius they would be able to get by somehow. But by himself…

"Well, Chuuyaaaa~ Is your brain so small you can't even answer a question?"

"Shut up, asshat. It's not like I have much choice." Chuuya hissed.

Dazai simply smiled, which, coupled with being forced to comply to this Tsunayoshi's demands, royally pissed him off. He and Dazai turned back to Tsunayoshi. Well, let's see how this goes.


	3. Something's...Off

**Summary for the Chapter:**

> What does the KHR cast think about Soukoku?

**Notes for the Chapter:**

> I'm writing this cause I'm super peeved that there are so little BSD x KHR fanfictions. So I decided, why not make some myself?

Chapter 3

'They're just...agreeing?' Tsuna thought, shocked. 

"Well? Are you just gonna stare at us all day?" Chuuya asked, still displeased at having to do this.

"How about some introductions before we discuss the favor? We can hardly discuss something if we don't even know your names~ " Dazai whined.

'Right, we haven't even introduced ourselves.' Tsuna thought.

"Well, I am the Vongola Decimo, Tsunayoshi Sawada. These are my guardians, Hayato Gokudera, Lambo Bovino, Takeshi Yamamoto, Chrome Dokuro, Mukuro Rokudo, Ryohei Sasagawa and Kyoya Hibari. And the arcobaleno, Reborn, Mammon, Fon, Skull, Verde, Colonello, Lal and Luce." Tsuna said, pointing to each person as he listed off their names.

A chorus of greetings resounded, as the guardians greeted/grunted/laughed/threatened the duo, and the arcobaleno greeted them like normal people. Mostly.

"Nice to meet you too~ I'm Dazai. Dazai Osamu. I'm a Port Mafia Executive. And this is my grumpy partner Chuuya Nakahara. He's an Executive too~ Since he's so short, you might have thought he was a child! But no, he's just a chibi.Together we make the duo Soukoku!" Dazai grinned as he cheerfully introduced himself.

"You piece of- !" Chuuya threw a punch at Dazai, but Dazai simply dodged it, dancing away whilst laughing at Chuuya.

"What~ it's true!" Dazai grinned.

Chuuya's response was to kick him.

"We should start discussing the favor, now." Tsuna said, trying to stop Chuuya from attempting to kill Dazai.

Chuuya huffed, turning to face Tsuna. Dazai smiled and went to stand next to Chuuya. 

"Ah, we'll be talking in the meeting room." Tsuna said, sweat dropping. 'Why is everyone I know always so weird?'

" 'Kay, let's go!" Dazai cheered, moving to follow Tsuna, Chuuya following a step behind him.

\---Time Skip, After Discussion Time---

Tsuna POV

I sighed, plopping down on the comfortable sofa in the living room. The discussion went… alright, all things considered. They briefed Dazai and Chuuya on the experiments, and gave them files containing information they had managed to collect about the experiments. Hayato kept threatening Dazai whenever he responded to Tsuna in a casual way, demanding Dazai 'show proper respect to the Tenth!' Takeshi tried defusing the situation, pissing Hayato off more, Ryohei tried punching Nakahara, Mukuro did Mukuro things, Hibari almost destroyed the room, Lambo whined, Skull shouted about a lot of things, the Arcobaleno caused more chaos, Dazai seemed quite amused, egging on Hayato and the rest occasionally, Nakahara just looked done with life and Reborn got annoyed enough to threaten everyone. Eventually they managed to finish the briefing, then left Soukoku to discuss plans by themselves, as they requested.

"Stupid brats, who do they think they are?" Hayato huffed, still miffed at Dazai and Chuuya's attitudes.

"Maa, maa, it's not like they did anything to hurt Tsuna, and they did agree to help us." Takeshi responded.

"Still-!"

Tsuna sighed, interrupting before this escalated. 

"Hayato, its fine. Takeshi is right, they agreed to help us, so we're the ones indebted to them."

Hayato reluctantly let it go.

"Besides, what were your impressions of Dazai and Nakahara?" Tsuna asked the group, curious about what they thought of the strange duo.

"They're stupid brats. I don't know how they'll be able to take care of the experiments. They don't seem all that strong." Hayato responded.

"Dazai's quite friendly! Nakahara seems kinda angry at everything though." Takeshi grinned.

"Dunno, they don't seem like much." Lambo responded from where laid on the couch.

"Nakahara is super extreme! He managed to block my punch with one hand!" Ryohei exclaimed.

"Kufufufu, we tried using an illusion on Dazai, but he just looked straight through it." Mukuro said, seemingly confused at the occurrence.

Chrome did not respond, merely nodding along to what Mukuro said.

"Hn." Hibari grunted, standing as far away from everyone else as possible.

Verde did not answer, seemingly tinkering with something.

Mammon simply asked for cash in exchange for their opinion.

Fon smiled and said nothing.

"They're weird, kora." Colonello said.

Lal did not say anything.

"They seemed nice enough!" Skull cheered.

"There's something… off about them." Reborn said. Tsuna's eyes widened. 'Reborn thinks they're off? My intuition is telling me that Nakahara is dangerous, really dangerous… Dazai is-  **_D_ ** **a** _ n _ **_G_ ** _ e _ r **N** **_o_ ** _ Sto _ **_P_ ** **W** _ H _ y **_MONSTER_ ** -' Tsuna  _ flinched _ .

"I cannot see anything about them." Yuni said.

Silence permeated the room.

"Yoo-hoo~ We're done~!" Dazai said, opening the door dramatically, a disgruntled Nakahara right behind him.

'Who were they?' Tsuna thought, watching the duo walk into the room.

'What have we brought here?'

**Notes for the Chapter:**

> Tsuna's intuition is being screwed with by Dazai's ability. Hyper Intuition can still function, but what it can tell is distorted and really doesn't make much sense. Hyper Intuition still functions cause it's not really Tsuna's ability. I've always thought it was weird how the Intuition just knows stuff. It's my head cannon that it's sort of a sentient being, tied to and pulled to those of the Vongola bloodline. It helps the descendents accomplish their Will.


	4. Who's The Monster Here?

**Summary for the Chapter:**

> Only a monster can kill a monster. Who's the real monster here?

**Notes for the Chapter:**

> Flames are the manifestation of the soul.

Chapter 4

Walking into the eerily silent room, Dazai and Chuuya blinked at the tense atmosphere. What in the world happened while they were discussing?

  


"We should go to the abandoned mansion now, since Dazai and I already formulated a plan to take them out." Chuuya said.

  


"Wow, Chuuya. For someone who  _ really _ didn't wanna do this, you sure are eager!" Dazai said with sparkly eyes and a goofy smile.

  


"Shut up shithead, the sooner we get there the sooner we can get it over and done with." Chuuya said, irritated.

  


"Right, there are cars prepared outside. Let's go." Tsuna said. They were helping them take care of the experiments, despite not knowing them. Even if they were dangerous individuals, well, that could be said for all of his family. Despite Tsuna's best efforts, wariness and dread pooled in his stomach.

  


Other than the slightly off feel about them, all the guardians and the arcobaleno agreed that they seemed perfectly normal. But something about the two just screamed danger. Something almost…  _ inhuman _ in nature.

  


Walking along with the rest of the group, Dazai hummed a tune under his breath. He could tell that they were wary in the way they all seemed to inch away from him and Chuuya. But they hadn't done anything to give them such an impression. On the contrary, they should have simply come off as immature and irritating. So why?

  


Chuuya walked alongside Dazai. He knew that the guardians and the arcobaleno were on edge around them. Honestly he didn't blame them. Dazai always seemed to have a presence that unnerved people, even when he tried to cover it up by playing up his immaturity and childish ways. After this favor, he and Dazai would be staying with them. To be frank he was really upset about this earlier, but now that he thought about it… well, about three years ago he started doubting his loyalty to Mori. He really only stayed because it was convenient and because Dazai was there. So having to join this group wouldn't really be all that bad. As long as Dazai remained here, he would too.

  


Getting in the car, which happened to be a giant limo, the guardians and the arcobaleno mostly sat on one side of the car, Reborn sitting on the far end nearest to where Dazai and Chuuya were sitting on the other side of the limo. Tsuna sat in between his guardians, so he was directly opposite Dazai and Chuuya.

  


As the car started to move, the passengers sat in silence.

  


"So, Dazai and Nakahara, you said you were part of the Port Mafia?" Tsuna said, breaking the tense silence that had settled around them.

  


"Yup~ I've been a part of it since I was just fourteen!" Dazai said, flashing a friendly smile over to Tsuna.

  


Chuuya nodded, and told Tsuna to call him Chuuya.

  


"Fourteen?" Tsuna asked.

  


"Mm. I was an unofficial member before that, but I got my first mission when I was fourteen." Dazai said nonchalantly, "That was also when I first met Chuuya!"

  


"You met on a mission?" Tsuna asked, mildly confused. Around him his guardians and the Arcobaleno also looked quite curious.

  


"Yep~ I was sent to check out some rumors, and I happened to chance upon Chuuya! In the end, the organization he used to belong to abandoned him, and so he joined the Port Mafia! I was the one to bring him into the organization!" Dazai responded, "That's when he started wearing that stupid hat of his."

  


Chuuya tried to punch Dazai.

  


"Ah, I see…" Tsuna said, not knowing how to match the weird warnings of his intuition to the seemingly childish duo.

  


The car stopped, and the passengers alighted. In front of them was the mansion that was the HQ of Estraneo.

  


Already, they spotted some dark figures lurking around the area.

  


"Well, we'll be starting now! All of you just stay there, 'kay?" Dazai said, turning slightly to face the group.

  


"You're going to handle them yourselves?", Some of the group asked, bewildered. They do know how many were killed or injured right? They thought the duo would be fighting alongside the rest of them, not by themselves!

  


"We'll be fine. It's not that big of a deal." Chuuya said, completely nonplussed.

  


As the duo turned to face the mansion, a large horde of experiments, which had apparently gathered while they were talking, started moving towards the duo. Dazai and Chuuya stepped forward, so as to ensure the group wasn't in the range of attack when the monsters attacked them.

  


Seeing the crowd draw near, Dazai released his flame, letting it spread to the vicinity. The air seemed to become heavy and oppressing, causing dread and fear to bloom in the hearts of all creatures in the range of his flames. Dazai stepped into the crowd, his flames curling around the monsters in range, nullifying their flames, cutting in sharply to get rid of their core, where the murky flames of the experiments stemmed from. As the monsters' wails, screams and inhuman shrieks filled the air, Dazai walked on unaffected. The experiments dropped to the ground, dead. After all, flames were the manifestation of the soul. Even these experiments would not be able to go on without anything to power them. Dazai idly wondered what it meant then, that his flames be so cold, so empty. Mori used to say his flames carried with them the presence of death, of nothingness.

  


The other monsters seemed to rear back, afraid of the strange being that managed to kill one of their own. Chuuya surged forward, kicking one of the experiments in the face. It wailed and tried to fight back, tried to drain the flame of the being which attacked it, but he could not. The flames in Chuuya seemed to have a barrier surrounding it. As if they were more than flames belonging to a simple human. Chuuya used his ability to destroy all the monsters which tried to attack him, leaving a trail of dismembered monsters in his wake. Dazai used his flames to finish off any monsters who managed to survive the wrath of Chuuya, and killed those who tried to escape. Just like a God of Destruction and the Grim Reaper which was sure to accompany it. Screams of the experiments filled the air, as Dazai and Chuuya worked through the large crowd. 

  


Finally, not one experiment remained standing, or alive.

  


Pulling back his flames, Dazai pulled them close to his core. Chuuya fixed his hat and coat, from where he stood beside Dazai. They turned to face the group.


	5. Humanity

**Summary for the Chapter:**

> Reborn and the rest, well, it's about time they saw what Soukoku was.

**Notes for the Chapter:**

> Its always been my headcannon that Dazai has a inhuman mindset. Sort of like if a god were to be on earth, in a human body. In canon, I view Oda as his link to his humanity. He saves orphans, joins the ADA, and does things considered kind or good, because of Oda's wish. Oda said that Dazai doesn't care about good or evil, and I think that also discourages the chances of Dazai being a truely kind person. Good and evil are concepts made by humans, after all. In this fic, Chuuya is his link to his humanity.
> 
> Chuuya is already inhuman because he's basically a god. It's my headcanon that Chuuya is kind. He cares. It's just that he can't afford to care. And what makes him a monster is the fact that he can bury his kindness so deep inside himself that he can't feel it anymore. Unless he wants to be kind, his kindness will remain buried. That's what makes him different from Reborn, for example. Reborn buries his empathy, kindness and everything nice. But, he can feel guilt. He just does his job despite that. Unlike Chuuya, which can just make himself heartless and cruel, Reborn just tries to bury it.
> 
> Well, at least that's my headcanon.

Chapter 5

As Reborn stepped out of the car, he found his eyes drifting towards the duo that Tsuna brought to their universe. There was an unnerving quality to them.He found himself on edge every time they moved or talked. 

  


When he first saw them, his first instinct was to  _ run _ . Terror gripped him, he could feel death's  **_-cold-cold-cold-_ ** embrace, so close- **ne** **_e_ ** d _ t _ **orun** can't _ fight _ **_GogOgEtAwaY-_ ** But he wasn't the World's Greatest Hitman for show, he managed to mask his fear, and watched as Tsuna asked them for a favor. 

  


Every time he looked at them a jolt of panic was sent through him. It was like staring in the face of death, or perhaps a god? His instincts were honed over years of being in his profession, and to doubt them would be foolish. That's why, as the duo said they could handle the creatures themselves, he did not doubt them. 

  


He watched the duo step forward. Dazai released his flames. Reborn nearly flinched back at the cold aura. Absentmindedly, he noted that the rest of the group had flinched harshly and even stepped back at the feeling of death in the air. He felt an overwhelming feeling of fear, and his heart felt heavy with dread.

  


Dazai's flames… they seemed more like the  _ lack _ of flames. Where humans would have flames, life, he seemed to have a void, empty space, like a hole had been carved into where his flames ought to be, it felt like nothingness.

  


As Dazai walked forward, the experiments fell to the ground dead, their screams filling the air, making his ears ring. Dazai looked like a harbinger of death.

  


The experiments, afraid, tried to move back, away from Dazai.

  


Chuuya surged forward, kicking at an experiment. Unaffected by the struggle of the experiment, he proceeded to crush it using some kind of power. Reborn thought he looked akin to a wrathful god. With a red aura around him, he truly looked terrifying. As Chuuya tore apart all that stood around him, Reborn watched as he decimated all who tried to touch him. The two of them, side by side, finished off the rest.

  


Dazai and Chuuya, standing side by side in land covered with the corpses of the dead experiments, with the kind of silence which instilled fear into the hearts of all who remained, seemed very much inhuman, and more like  **_monsters._ **

  


And that was terrifying. For even he was not exempted from the label of human. Hitmen, killers, mafia bosses all the same were still human. 

  


Yet the duo, Dazai and Chuuya, Soukoku, were monsters. And so, even if Reborn was the strongest human to ever live, he would still fear monsters, kinder monsters, crueler monsters, lying monsters, he would fear them all the same.

  


Tsuna felt his fingers shaking. His mind seemed to go blank, as he stared at the carnage. What was this?

  


Soukoku turned to look at them.

  


He flinched, trembling. He could feel the fear from his guardians and the Arcobaleno.

  


All at once, they knew. The two who stood before them were not  _ humans,  _ they were  **_monsters._ **

  


Dazai turned to face the group. They flinched away. Well, it seems they were afraid of Dazai and Chuuya now. How amusing. Weren't they the ones who asked them to wipe out the monsters? Why were they so afraid now that they'd done what they asked them to do?

  


Well, he supposed it was a normal reaction. He supposed they must have made quite a sight, surrounded by corpses and all.

  


He wondered if the fear bled into respect, too?

  


He grinned. A twisted, empty thing. They seemed to tremble even harder at the sight.

  


Chuuya turned to face the group, noting how they flinched and trembled.

  


He supposed this was his fate. To always be feared…as a monster.

  


He did care. He cared so very much. But, kindness did not do well in the mafia. So he buried it deep within himself, only caring for his men, and his partner. Dazai… understood. Sort of. 

  


Whereas he  _ became  _ a monster, Dazai was always a monster. Chuuya was a god, and Dazai was a harbinger of death. Chuuya was tied to humanity by his kindness, and he liked to think Dazai was tied to his humanity by him.

  


Humans would always fear monsters. For they have never encountered one so unlike themselves.

  


He stared blankly at the group, seeing Dazai smile at the group from the corner of his eye. They trembled harder.

  


Dazai and Chuuya started to walk towards the group at the same time.

  


They approached slowly, as if trying not to scare them away.

  


The group looked one wrong move away from bolting.

  


Dazai and Chuuya stopped right before the group.

  


Dazai fixed his expression, making sure to firmly reattach his mask of a friendly person.

  


Chuuya let his kindness take hold for a bit, softening his gaze.

  


The group did not relax, but they did calm down a bit. They were no longer trembling, or if they were, it was only barely.

  


"Well~ We've accomplished our side of the deal!" Dazai said, the change from cold and blank to warm and friendly was jarring.

  


"R-Right. You can stay at the Vongola mansion. If you want, you can also join the Vongola. If you don't, you'll still be welcomed at the mansion all the same." Tsuna said.

  


"Can we have alcohol?" Chuuya asked.

  


"Ah, yes, of course." Tsuna answered.

  


"Wow~ Already asking about alcohol huh, slug. You really  _ are  _ an alcoholic!"

  


"Shut up you bandage obsessed suicidal maniac!"

  


"Oh? Is Chibi angry~?"

  


"You…!"

  


Tsuna watched as the two bickered, the warm interaction seemingly diffusing most of the tension that had built up.

  


As they got into the car Tsuna wondered if this was what it felt like to have a guillotine over your head.


	6. Epilogue

**Summary for the Chapter:**

> The story was really finished last chapter, but here's a brief epilouge. Maybe I'll do some oneshots about this universe, I'll make sure to add them to the Bungou Stray Dogs and KHR list.

Chapter 6  
Once they arrived back at the mansion, Chuuya and Dazai were shown to their rooms.

Tsuna and the others went back to doing what they usually did.

Chuuya and Dazai decided to join Vongola. Mostly because they were bored, and they had nothing else to do, really.

Over the next month, Soukoku became quite infamous. Not one Famigila didn't know about the deadly duo of Vongola.

Dazai, one half of Soukoku, was dubbed Demon Prodigy by the mafia world, ironically.

Chuuya, the other half of Soukoku, was dubbed Wrathful God by the mafia world, causing Dazai to double over due to laughter once he heard the stupid moniker given to Chuuya.

Tsuna and his guardians got friendlier with the two, but there were moments when the fear they felt would overwhelm them.

Reborn, to the surprise of everyone else, agrees easily to any favors the duo ask of him. Well, easily compared to when anyone else asks him for a favor, at least.

The rest of the Arcobaleno are still kind of on edge near them, but they are friendly enough to Soukoku.

Such is the story of the way Soukoku joined Vongola.

**Notes for the Chapter:**

> I hope you enjoyed. I really only wrote this because I was angry at the lack of BSD x KHR fanfics, but I hope you enjoyed my subpar writing anyways. I appreciate you taking the time to read this. :)


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